"Corrupt federally licensed gun dealers: Federally licensed gun dealers send more guns to the criminal market than any other single source. Nearly 60% of the guns used in crime are traced back to a small number—just 1.2%—of crooked gun dealers. Corrupt dealers frequently have high numbers of missing guns, in many cases because they’re selling guns “off the books” to private sellers and criminals. In 2005, the ATF examined 3,083 gun dealers and found 12,274 “missing” firearms."
Just because it won't eliminate the problem doesn't mean we shouldn't work to reduce the problem